GB2055179A

GB2055179A - Valve

Info

Publication number: GB2055179A
Application number: GB8023906A
Authority: GB
Original assignee: Karl Dungs GmbH and Co KG
Current assignee: Karl Dungs GmbH and Co KG
Priority date: 1979-07-25
Filing date: 1980-07-22
Publication date: 1981-02-25
Also published as: IT8023559A0; DE2930131A1; GB2055179B; FR2462631A1; IT1131734B; NL8003780A

Abstract

The invention relates to a valve with a housing and a valve seat (10) located therein and comprising a frustoconical sealing surface (11), with which valve seat a movable valve member (6) is associated which is able to move on the valve seat towards and away from the latter, which in the closed position bears in a tight manner against the valve seat (10) and separates two apertures (17, 18) from each other in a tight manner, with at least one aperture connected to one of housing connections (15, 16). In order to be able to use the valve as a two-way valve and in particular for checking the tightness in the case of gas fired installations, a third connection not shown is provided in the housing (1) and is connected to the part (13) of the inside of the housing which is separated in a tight manner from the first two connections (15, 16) when the movable valve member bears in a tight manner against the valve seat (10). <IMAGE>

Description

SPECIFICATION Valve The invention relates to a valve with a housing and a valve seat located therein and comprising a sealing surface of frustoconical shape, associated with which valve seat is a movable valve member able to move on the valve seat towards and away from the latter, which in the closed position bears in a tight manner against the valve seat and separates two connections for the intake or discharge of a medium from each other in a tight manner, with at least one aperture opening into the sealing surface, which aperture is connected to one of the connections.

Valves of this type are known for example from German AS 12 12 802 or GB PS 492 493. In these known valves, not just one aperture opens into the surface of the valve seat, but two apertures open into the surface of the valve seat, which apertures are respectively connected to one of the connections. Thus, embodiments of valves are known in which the movable valve member is divided into two parts, which parts can be pressed in the closed position by way of a common drive against the valve seat associated therewith (US PS 959 349).

It is the object of the present invention to extend the range of application of these known valves due to the fact that they can be used as two-way valves.

This object is achieved according to the invention due to the fact that a third connection is provided in the housing and is connected to the part of the interior of the housing which is separated in a tight manner from the two first connections when the movable valve member bears in a tight manner against the valve seat.

Thus, this valve comprises three connections, whereof one is connected to the aperture opening into the sealing surface, whereas the other two are connected to the parts of the interior of the housing which are separated from each other by the movable valve member bearing in a tight manner against the sealing surface and border the two end faces of the movable valve member. A valve of this type with three connections facilitates a plurality of advantageous applications.

A particularly preferred range of application for a valve of this type with three connections is in the case of gas supply pipes to heating burners. These supply pipes or the valves which block the flow of gas must be checked as regards their tightness, since leakages could lead to accidents, especially if gas escapes unnoticed, accumulates, forms an explosive mixture and is ignited by a chance spark.

For this purpose, previously two valves were always used and when the valves were closed the space between the two valves was checked due to the fact that a varying pressure was produced and the change in this varying pressure was monitored over a period of time. If the speed of the change in the varying pressure was below a certain value, then the two valves were regarded as sufficiently tight. The checking operation thus takes place preferably in the manner that the checking space was provided with a pressure monitor in which case a timer was switched on at the beginning of the checking operation and an alarm was initiated by the pressure monitor if the latter is thrown-over before the expiration of the time period.It was a drawback of these known monitoring devices that the volume of the measuring space between the two valves fluctuates from installation to installation and it is therefore necessary to ascertain and pre-set a different time interval for each operation, because the time interval, tightness and volume of the measuring space are interdependent. For the purpose of simplification, it has already been proposed (German OS 28 37 756), to use a two-way valve instead of two valves and to utilise the space between the two movable valve members as a measuring chamber. Consequently, the measuring times for any installation can be predetermined previously and do not need to be ascertained and pre-set on each occasion. It is thus possible to eliminate sources of error when ascertaining and pre-setting the measuring times.However, when using the valve according to the invention, it is also possible to make an additional saving on structural expenditure. In this case, the connection which is not connected to an aperture opening into the sealing surface of the valve seat is connected to the measuring chamber, which is defined by the housing and the movable valve member located in the closed position.

Furthermore, the valve according to the invention has further areas of application. For example it may be used as a two-way valve, which is able to replace two conventional valves in cases where one feed pipe simultaneously supplies two outlet pipes, which lead for example to different consumer devices. Thus, the use of the valve according to the invention is particularly advantageous if it is necessary to ensure that the two consumer devices are respectively supplied simultaneously. However, likewise, this valve with three connections may advantageously be used as a mixing valve, namely if two media arrive through two pipes and are discharged by way of a third pipe.

In preferred embodiments of the invention, two apertures open into the frustoconical sealing surface and are each provided with a connection, whereby the two apertures are located opposite each other and extend respectively over approximately 1 800 of the periphery of the sealing surface. This embodiment provides a favourable through-flow characteristic.

In a preferred embodiment of the invention, the two spaces adjoining the end face of the movable valve member constructed as a valve disc, when the valve is closed, are connected to each other.

This is an advantage if the valve is used for checking for leakages, because then the total space serving as a measuring chamber has a greater volume without the overall size of the valve having to be changed. A pressure monitor and an apparatus for changing the pressure at the beginning of the tightness-checking operation are connected to this measuring chamber.

In a preferred embodiment of the invention, the valve drive is attached to oppositely disposed sides of the housing. This has the advantage that the valve drive may be located seiectively on two different sides, which may facilitate the installation of the valve in the case of unfavourable installation situations.

The construction of the movable valve member can be varied in many ways. In a preferred embodiment it has a rigid core with attached mountings for the positive attachment of the resilient sealing jacket. In this case, the resilient sealing jacket can be slipped-over or according to a further preferred embodiment, additionally vulcanised thereon or stuck thereto.

In order to ensure that in the closed position, the movable valve member bears in a tight manner, it is necessary that it is guided in line with, i.e. coaxially, with the valve seat. However, when producing the housing and the drive assembly, for example an electromagnet, an exact alignment cannot always be ensured. Very small alignment errors are compensated for by the elasticity of the sealing jacket. If greater alignment errors are to be compensated for, without jeopardising the tightness, the resilient sealing jacket must be relatively elastic. However, this is a drawback if the valve is to be used with relatively high pressures of the media and it is a further drawback that greater wear and thus a reduced life expectancy may occur.Therefore, in a preferred embodiment of the invention, the movable valve member comprises two sections able to move with respect to each other and in the closed position respectively closing off one of the two apertures in a tight manner. This has the advantage that even appreciable alignment errors can be compensated for automatically, without having to use a relatively soft material for the sealing jacket and without excessive wear phenomena occurring. Preferably, in a further embodiment, the two sections are connected to the drive by way of a splined or lever, in particular a toggle linkage.Splined or toggle linkages of this type not only have a favourable power characteristic along the stroke of the drive. they also produce a high pressing force and on the other hand make it possible to carry out the closing movement such that it not only has components in the axial direction of the valve cone but also components at right angles thereto, I.e. at right angles to the surface of the aperture in the sealing surface. In this case, the two sections are biased by a spring with respect to their linkage or with respect to each other.

In a further preferred embodiment of the invention, the two sections are respectively mounted on a guide bolt attached rigidly to the drive. In this case, the two guide bolts are located in a common plane, in which the axis of rotational symmetry of the valve seat is also located. The two guide bolts together enclose an acute angle pointing away from the drive which is at least approximately as great as the angle of the cone of the sealing surface. This type of construction provides favourable kinematics of the valve drive.

Further details and embodiments of the present invention will become apparent from the ensuing description of embodiments illustrated in the drawings in conjunction with the claims. The illustrations are simplified, diagrammatic and restricted to what is essential: Figure 1 is a section through a valve including the drive, Figure 2 is a section on line Il-Il of Figure 1.

Figure 3 is a view in the direction of arrow III of Figure 1, omitting the drive and Figure 4 a, b are respectively a section through a valve without drive and with a divided movable valve member.

The valve illustrated in Figure 1 comprises a housing 1 with an electromagnet 3 attached thereto with the interposition of a flanged cover 2 serving for centring, which electromagnet 3 is supplied with power by way of a junction box 4.

An armature 5 as the movable part of the electromagnet 3 is guided in a bore in the flanged cover 2 and at its end remote from the electromagnet 3 supports a movable valve member 6, which comprises a holder 7 attached to the armature 5 and a sealing jacket 8 held in a form-hugging manner on the holder 7 and vulcanised thereon, which jacket consists of a resilient, in particular a rubber material. When the electromagnet 3 is energised, the movable valve member 6 is lifted against the action of a closing spring 9 from a valve seat 10, the sealing surface 11 which is in the shape of a frustoconical shell.

Similarly, the surface of the sealing jacket 8, which comes to bear against the sealing surface 11 in the closed position of the valve has a surface corresponding to a frustoconical shell. The direction of movement of the movable valve member 6, its axis of rotational symmetry and the axis of rotational symmetry of the valve seat 10 coincide.

The valve seat 10 is formed in the housing 1, in which case its plane is at right angles to the driving movement of the electromagnet 3 and is located at a mid-point of the housing 1. Adjoining the plane of the valve seat 10 is a drive chamber 12. whereas a regulating chamber 13 adjoins the valve seat 10 on the opposite side. The two chambers 12 and 13 are machined in the housing 1 and on the one hand when the valve is closed, are separated from each other and defined spatially by the movable valve member 6. On the other hand, the drive chamber 12 is defined by the flanged. cover 2, whereas the regulating chamber 13 is closed off externally by a cover 14. If the housing 1 is used for a regulator, then in place of the flanged cover 14, the drive for the movable valve member is attached and the flanged cover 2 with the electromagnet 3 is closed off by a cover closing the drive chamber 12.

Two connection chambers 1 5 and 16 are provided on two opposing sides which are approximately parallel to the axis of rotational symmetry of the valve seat and movable sealing member Connections which are not illustrated can be provided on the free end faces.

Starting from the connection chambers 1 5 and 1 6. a slot-like recess 17,18 respectively is formed in the valve seat 1 0, which recesses open into the sealing surface 11 of the valve seat 10 by an aperture covering approximately 1 800 of the valve seat. The common plane of the two slot-like recesses 1 7 and 1 8 is at right angles to the direction of movement or the axis of rotational symmetry of the movable valve member 6. The apertures by which the recesses 1 7 and 1 8 open into the sealing surface 11 are closed off in a tight manner by the sealing jacket 8, when the valve is closed.When the valve is open, after only one stroke of the movable valve member by the height of the slot-like recesses 1 7 and 1 8 plus a certain extra length, the full cross-section of passage of the recesses 1 7 and 1 8 is free, so that the valve is a free flow valve.

It will be understood that in place of the recesses 1 7 and 1 8, only one of these recesses may be provided and in this case, in place of the cover 14, a connection for the supply or discharge of medium is provided.

Figures 2 and 3 show the housing 1 in more detail, whereby in these figures only the housing 1 is illustrated without the movable valve member, without the cover, flanged cover and drive. As shown clearly in Figure 2, the recesses 17, 18 extend virtually to the central plane, in which the axis of rotational symmetry of the movable valve member and valve seat is located. Provided in the vicinity of this central plane are cross-pieces 1 9 arranged parallel to the axis of rotational symmetry of the valve seat, up to which the recesses 1 7 and 1 8 extend over their depth. Also machined in the housing are through holes 20, which serve for attaching the aforementioned connections which are not shown, which connect the connection chambers 1 5 and 1 6 to an inlet or outlet pipe.

In the embodiment of a valve illustrated in Figure 4a, the electromagnet 3 of the drive is omitted. This embodiment of the valve differs from the embodiments illustrated previously due to the fact that the movable valve member 36 is divided into two sections 37 and 38, the plane of separation of which coincides with the central plane of the two oppositely disposed grooves 32 in the housing 1. Otherwise, the construction of the movable valve member 36 corresponds to that of the valve member 6. The two sections 37 and 38 are supported in a resilient manner by way of a compression spring against a driving armature 41 of the electromagnet which is not shown. The drive connection takes place by way of a toggle linkage, whereof the toggle is formed by a bolt 42, about the axis of which guide rods 43 and 44 are able to pivot.The other ends of the guide rods 43 and 44 are connected by means of bolts 45 and 46 to the two sections 37 and 38. The axes of all three bolts 42, 45 and 46 are parallel to the plane of the slot-like recesses 1 7 and 18 and thus perpendicular to the direction of movement of the armature 41. When the armature 41 moves downwards under the force of the spring into the closed position, the sealing jackets of the sections 37 and 38 come to bear against the sealing surface 11 and close off the openings of the recesses 1 7 and 1 8 in a tight manner. Alignment errors can thus be eliminated without reducing the life expectancy and above all without increasing the wear of the sealing jacket by abrasion.

In the embodiment illustrated in Figure 4b with a divided movable valve member 56, the two sections 57 and 58 are respectively mounted to move on a guide bolt 59, 60 in the axial direction thereof. The two guide bolts 59 and 60 are pressed into a plate 62 located on an armature 61 of the driving electromagnet which is not otherwise illustrated, whereby the two guide bolts 59 and 60 lie in a common plane, in which the axis of rotational symmetry and the direction of movement of the armature are also located.

However, the two guide bolts 59 and 60 are inclined towards each other and with the axis of rotational symmetry enclose an acute angle whereof the apex points away from the driving electromagent. Due to a helical compression spring 63 located between the two sections 57 and 58 on the one hand and the plate 62, the two sections 57 and 58 are held in abutment against a disc 64, which is in turn held at the free ends of the guide bolts 59 and 60 by the latter. Due to this type of movable mounting of the two sections 57 and 58, alignment errors can be compensated for easily, because if, at the time of the closing movement, one of the two sections 57 or 58 comes into abutment sooner than the other, the armature with the guide bolt may move further axially, whereby owing to the inclined position of the guide bolts, only the pressing force of the respective section on the sealing surface 11 is increased. During this movement, the other section likewise comes into abutment before the armature 61 has terminated its lifting movement.

It will be understood that the invention is not restricted to the embodiments illustrated, but that variations thereof are possible without diverging from the scope of the invention. In particular, certain of the features of the invention may be used alone or in combination.

Claims

1. A valve comprising a housing, a valve seat located therein having a frustoconical sealing surface, a movable valve member associated with the valve seat and able to move towards and away from the valve seat such that in the closed position it bears against the valve seat in a sealing manner to separate two connections from each other, at least one aperture opening into the sealing surface and connected to one of the connections, and a third connection is provided in the housing and connected to the part of the interior of the housing which is separated in a sealing manner from the two first connections when the movable valve member bears in a sealing manner against the valve seat.

2. A valve according to claim 1 , wherein two aperture open into the frustoconical sealing surface and are respectively connected to a connection and the two apertures are located opposite each other and respectively extend over approximately 1 80C of the periphery of the sealing surface.

3. A valve according to claim 2, wherein when the valve is closed the two spaces adjoining the end faces of the movable valve member constructed as a valve disc, are connected to each other.

4. A valve according to any one of claims 1 to 3, wherein the valve drive is attached to opposite sides of the housing.

5. A valve according to any one of the preceding claims, wherein the movable valve member comprises a rigid core with attached mountings for the form-locking attachment of a resilient jacket.

6. A valve according to claim 5, wherein the resilient sealing jacket is attached by vulcanisation.

7. A valve according to any one of claims 2 to 6, wherein the movable valve member comprises two sections able to move with respect to each other and in the closed position respectively closing off in a tight manner one of the two apertures opening into the sealing surface.

8. A valve according to claim 7, wherein the two sections are connected to the drive by way of a splined connection or a lever, in particular a toggle linkage.

9. A valve according to claim 7 or 8, wherein the two sections are biased by a spring with respect to their linkage or with respect to each other.

10. A valve according to claim 7 or 9, wherein the two sections are respectively mounted on a guide bolt attached rigidly to the drive.

11. A valve according to claim 10, wherein the two guide bolts are in a common plane, in which the axis of rotational symmetry of the valve seat is also located, and the two guide bolts together form an acute angle pointing away from the drive, said angle being at least approximately as large as the angle of the cone of the sealing surface.

12. A valve substantially as herein described with reference to and as illustrated in the accompanying drawings.